Bending jig



Feb. z2, 1966 N P, HOUSE, JR 3,236,089

BENDING JIG Filed Feb. 13, 1962 2 Sheets-Sheet 1 NTV Norman P. Lohouse, Jr.

ATTORNEY N. P. LoHousE, JR

BENDING JIG F eb. 22, 1966 Filed Feb. 13, 1962 52 Fig. 3. 52

Fig. 6.

Fig. 5.

2 Sheecs--Sheezil 2 INVENTOR Norman P. Lohouse, Jr.

ATTORNEY United States Patent Chico 3,236,089 Patented Feb. 22, 1966 3,236,089 BENDING .IIG Norman P. Lohouse, Jr., Eggertsville, N.Y., assignor to American Radiator & Standard Sanitary Corporation, New York, N.Y., a corporation of Delaware Filed Feb. 13, 1962, Ser. No. 173,093 4 Claims. (Cl. 72-458) This invention relates to an improved device for bending tubes, pipes, rods, and other similar items.

Heretofore, complex devices for bending tubes in a multiple number of planes have been used. These devices were generally cumbersome and not readily transportable from place lto place as might be desired when working on a job. The simpler bending devices that were available could not conveniently be Iused `for forming bends in a multiple number of planes. In certain applications, however, such as for example in the installation of base board heating in homes and buildings, it was desirable to have a tube bender of relatively simple construction in order that it could be easily carried from place to fplace and which was able to be used for forming bends in a multiple number of planes.

It is, therefore, an object of the present invention to provide an improved bending apparatus which is readily portable and which is capable of forming bends in different planes.

Another object of the invention is to provide a simple jig for forming bends in different planes without having to change the initial position of the tube in the jig.

Still another object of the invention is the provision of an improved device for bending slender members of various sizes in different arrangements.

A further object of the present invention is the provision of an improved bending apparatu-s for forming two bends, the distance between which may be easily varied.

Other objects and features of the invention will appear as the description of the particular physical embodiment selected to illustrate the invention progresses. In the accompanying drawings, which form a part of this specification, like characters of reference have been applied to corresponding parts throughout the several views which make up the drawings wherein:

FIGURE 1 is a plan view of the improved bending device of the present invention.

FIGURE 2 is a side elevation looking in the direction of the arrows 2 2 in FIGURE 1.

FIGURE 3 is a side elevation looking in the direction of the arrows 3-3 in FIGURE 2.

FIGURE 4 is a partial sectional elevation taken along the line 4--4 in FIGURE 1.

FIGURE 5 is a side elevation of the ller piece.

FIGURE 6 is a side elevation of the filler piece looking in the direction of the arrows 6-6 in FIGURE 5.

With specific reference to the form of the present invention illustrated in the drawings, the bending apparatus is comprised Iof a base member 10 having a forward section with angularly displaced slots or channels 12, 14, 16, for receiving one end of the tubing to be bent and a rear section at which the slots converge to a single channel 18. A support arm 17 is secured to the front section of the base, such as by the bolts 19, to support the base member 10 in a pipe vise or other suitable work holding means. A side wall on each of slots 12 and 16 converge into the channel 18 and have generally curvilinear surfaces 20 and 22 respectively.

By :placing yone section of a straight tube in either one of the slots 12 or 16 and moving another section of the tube horizontally and transversely to its longitudinal axis within the channel 18, the tube will bend around the curved surface 20 or 22. If the tube is moved all the Way to one side of the channel 18, then the angle of the bend formed in the tube will be equal to the angle between the axes of the channel 18 and the groove 12 or 16, which in the present case is about 20 degrees.

In order to form a second bend in the same length of tube without changing the initial position of the tube in the slot 12 or 16, means are employed at one end of the channel 18 providing a curvilinear surface about which the second bend may be made in a plane different from the plane of the first bend. This means consists of a forming member 24 having a rib 25 and a portion delining a curved surface 26, one end of which is tangential to the bottom surface of channel 18 while the other end terminates below the bottom surface of channel 18. The -forming member 24 is secured to rearwardly projecting extensions 28, 30, of the base 10 by any suitable means such as the angle brackets 32, 34 which are bolted to the forming member 24 by the bolts 36 and to the base extensions 28, 30 by the bolts 38, 40, 42. The curved surface 26 is at least as wide as the channel 18 in order to form a curved continuation of the bottom surface of channel 18 for the complete width thereof.

Without changing the position Iof the tubing in the slot 12 or 16, a second bend may be formed in the same length of tubing by moving the tubing in a plane substantially perpendicular to the plane in which it was moved in making the rst bend, that is downwardly as viewed in FIGURE 2. The -second bend, which is formed in this manner over the curved surface 26, will be approximately degrees and in a direction and plane transverse to the :plane of the rst bend.

In order to vary the distance of the straight line portion of the tube between the two bends, means are provided to change the position of the forming member 24 relative to the base 10. The last mentioned means consists of slots 44, 46, in the angle brackets 32, 34 respectively which permit the angle brackets 32, 34 to slide longitudinally to various positions relative to the base 10. For example, the forming member 24 may be moved from the solid line position shown in FIGURE 2 by removing the bolts 42, loosening the bolts 38, 40 and sliding the forming member 24 to the dotted line position of FIG- URE 2. The bolts 38, 40 are then tightened to secure the forming member 24 and angle brackets 32, 34 in the new position.

It will be appreciated that if variable adjustment is not necessary and only two specific adjustments are needed, instead of employing slots 44, 46, holes could be substituted whereby one set of holes would be used for one adjustment and another set of holes for another adjustment. For example, if the distance between the bolts 38 and 40 equaled the distance between the bolts 40 and 42, the position of the forming member 24 shown by solid lines in FIGURE 2 may be changed by removing the bolts 38, 40, 42, moving the forming member 24 to the dotted line position shown in FIGURE 2 and tightening the bolts 38, 40 to hold the forming member 24 in place.

In Order to support the tubing from bending laterally Within the channel 18 as the second bend is being made, a filler piece 48 may be inserted in one side of the channel 18 alongside the tube. The ller piece 48 is placed in the channel after the lirst bend has been made. The side of the channel 18 on which the liller piece 48 is placed will depend on which of the slots 12 or 16 was used in making the rst bend. For example, if the slot 12 was used in making the rst bend, the iiller piece 48 would be placed in the channel as shown in FIGURE l. Thus when the second bend is made, one side of the filler piece will support one side of the tube to prevent lateral distortion of the tube.

To `support the tubing from bending upwardly in the channel 18, a cover plate 50 is provided which is secured to the base by thumb screws 52. As shown in FIG- URE l, the cover plate extends beyond the channel 18 over the surfaces 20, 22, so that it can, if desired support the upper portion of the tube as the first bend is being formed. The cover plate 50 also extends rearwardly to support the upper part of the tube when the forming member 24 is extended to the solid line position shown in FIGURE 2.

The cover plate 50 may remain in position as the tube is being inserted in the apparatus and the two bends are being made since the tubing can slide longitudinally through the channel 18 into the slot 12, 14, or 16. To remove the bent tubing from the apparatus, the cover plate 50 may be quickly removed by loosening the thumb screws 52. In some cases it may be desirable to form the first bend without the cover plate 50 in place and while the cover plate 50 is desirable when the second bend is formed, it is also possible to manually support the tubing when this second bend is made. The cover 50 need not be removed from the base 10 to insert or withdraw the filler piece 48 since the filler piece 48 can be slid longitudinally in the channel 18 underneath the cover plate 50.

In addition to being capable of making two bends in different planes, the apparatus of the present invention may also be used to make a single bend on the forming member 24. By placing the tubing in the center slot 14 and moving one end of the tube downwardly, as viewed in FIGURE 2, a bend will be formed conforming to the 90 curve 26 of the forming member 24. The ller piece 48 is not required in this operation. But the cover plate 50 may be held in place on the base 10 to support the upper part of the tube as the bend is being made. While it is possible to bend many tubes and elongated rods without disforming the diameters thereof, Iwhen soft tubing is bent the side walls sometimes have a tendency to collape. To avoid this when making any of the foregoing bends, suitable bending support springs, well known in the art, may be inserted inside of the tubing before it is bent to prevent this from occurring.

In order to adapt the apparatus for handling different diameters of tubing, inserts may be provided to fit the slots-12, 14, 16, By placing the inserts in the slots, tubing having ya smaller diameter than the width of the slots Iinay be adequately supported by the inserts during the bending operation. For the purpose of providing support above the channel 18 when different size tubing is |being bent, cover plates having varying sizes and thicknesses at the central portion may likewise be provided. A single cover plate having one flat surface and a raised centralportion 54 on the opposite face may be used for handling two different sizes of tubing. For example, 5% -tube may be adequately supported with the cover plate in position as shown in FIGURE 3, while 1/2 tubing may be bent if the position of the cover plate is reversed so that the raised central portion 54 projects into the channel 18.

Similarly, different size ller pieces 48 may be used for different size tubing. However, a single filler piece 48 may be used fortwo different size tubing by making it in a rectangular form as shown in FIGURE 5 so that each dimension of the rectangle corresponds to the difference between the width of channel 18 and the diameters of the two tubes to be bent.

. It is to be noted that although the forming member 24 is shown as having a surface 26 which extends over a 90 degree arc, the forming member may Abe constructed to produce a bend of any angle and is not necessarily limited toproducing a 90 degree bend.

In cases where it is desired to vary the distance from the first bend 'to the end of the tube, adjustable stops 55 slidable in the slots 12, 14, 16 may be provided to abut the longitudinal end of the tubes. Thus when a tube is inserted in the slots 12, 14, 16, the bends will occur at the desired distances from the end of the tube. Where such adjustability is not needed, the` stops may be permanently formed in the slots.

The selection of whether to use slot 12 or 16 will depend on whether a right handed or left handed bend, relative to the second bend, is desired.

F or example, when installing base board heating panels in homes, it is often necessary to drop the tubing below the oor level, when by-passing a doorway, bathtubs, sinks, etc. and come up on the other side of the obstruction. Generally, thecoucrete foundation of the building is wider than the walls carried by the foundation. Therefore, the tubing after passing down through the floor, has to be bent (usually to about a 20 degree angle), to avoid the foundation. This bend extends the tubing inwardly from the wall -suiciently to avoid the concrete foundation immediately below where the tubing passes through the oor. The tubing then has to be bent again 90 degrees at another position so that it will run in a horizontal direction beneath the doorway or other obstruction. This second bend lies in Ia different plane from the plane of the first bend.

The rst bend is in a vertical plane and the second bend is in a plane angularly displaced with respect to the plane first bend. The particular arrangement of the two bends relative to one another will depend on whether the tubing is to pass -underneath the doorway or obstruction from left to right, or from right to left. Thus if the tubing is to pass underneath the doorway from left to right, as viewed from the inside of the room, then the channel 12 would be used to make the first bend. If it is to pass from right to left, then channel 16 would be used for making the iirst bend.

Means may be provided to pivot the front section of the base containing the slots 12, 14, 16 relative to the rear section containing the channel 18 in order to vary the angle of the first bend. However, the embodiment of the invention illustrated in the drawings is particularly adaptable for forming a great many tubes having bends of a particular angular configuration, so that many tubes may be formed exactly alike.

Insteadof clamping the handle 17 to a holding clamp, the bending apparatus could also be used in `a manner similar to a bending hickey. In this case one end of the tubing may be either held in a fixed position by a suitable holding means or may be laid on the oor for support. The apparatus of the present invention would then be moved rel-ative to the'tubing to form the bend. For example, the rst bend may be made using the slot 12 er 16 by moving the base 10 and the portion of the tube to `be bent relative to the remainder of the tube. To make the second bend on thev curved surface 26, the opposite end of the tube may be moved over the form-ing member 24 or alternatively, the opposite end of the tube may be supported on the floor or in a suitable holding means as the frame 10 is moved relative to the supported end.

From the foregoing it will be evident I have provided a simple bending jig which can be readily used on the job or in a shop for making a multiple number of bends in different planes in elongated materials such as tubes, pipes, rods, bars and similar structures.

The invention herein-above described may be varied in construction within the scope of the claims, for the particular device yselected to illustrate the invention is but one of many possible embodiments of the same. The invention, therefore, is not to` :be restricted to the precise details -of the structure shown and described.

What is claimed is:

l. Tube bending apparatus comprising a base structure having a longitudinal axis;

said structure having a first relatively wide channel extending therein along its longitudinal axis;

said base structure having a second relatively narrow channel extending from Ian end of the first channel at an 'angle thereto;

Said channels being in a common plane whereby a tube having a diameter corresponding to the width of the second channel can be extended obliquely through the wide channel into -a snug t within the second channel, after which the exposed portion of the tube can be drawn against a side surface of the wide channel to form a first tube bend having an angularity corresponding to the angularity between channels;

said apparatus further comprising a straight surfaced insert structure insertable into the wide channel after -the tube has been bent as aforementioned, whereby said insert structure then c-auses the tube to have a snug tit in the wide channel;

said apparatus further comprising a forming member carried by said base structure;

said forming member having a convex curvilinear anvil surface located in -a plane angled to the plane of the first and second channels;

said curvilinear surface including a surface portion aligned with the 'bottom surface of the rst channel, whereby the tube can lbe bent around the curvilinear surface to effect a second bend therein.

2. The apparat-us of clairn 1 and further comprising means for adjusting the forming member position in the direction of the rst channel without disturbing the alignment of the aforementioned curvilinear surface portion and channel bottom surface, whereby to vary the distance between the rst and second tube bends.

i3. The apparatus of claim 1 and further comprising cover means adapted to overlie the wide channel and engage the tube surface while the tube is being bent around the forming member curvilinear surface.

4. The apparatus of claim 1 wherein said base structure is provided with a third relatively narrow channel diverging from an end of the wide channel, the three channels lying in a common plane and presenting a Y- shaped configuration in plan;

the third channel being used as an alternate to the second channel to provide different mirror image first bends.

References Cited bythe Examiner UNITED STATES PATENTS 1,679,954 8/ 1928 Webber 153-,32 2,306,224 12/1942 Parker 153-40 2,341,178 2/1944 Duer 153-40 2,356,716 8/1944 Wheeler 81-15 FOREIGN PATENTS 589,561 6/1925 France.

CHARLES W. LANHAM, Primary Examiner.

WHITMORE A. WILTZ, Examiner.

G. L. MILHOLLIN, R. D. GREFE, Assistant Examiners 

1. TUBE BENDING APPARATUS COMPRISING A BASE STRUCTURE HAVING A LONGITUDNAL AXIS; SAID STRUCTURE HAVING A FIRST RELATIVELY WIDE CHANNEL EXTENDING THEREIN ALONG ITS LONGITUDINAL AXIS; SAID BASE STRUCTURE HAVING A SECOND RELATIVELY NARROW CHANNEL EXTENDING FROM AN END OF THE FIRST CHANNEL AT AN ANGLE THERETO; SAID CHANNELS BEING IN A COMMON PLANE WHEREBY A TUBE HAVING A DIAMETER CORRESPONDING TO THE WIDTH OF THE SECOND CHANNEL CAN BE EXTENDED OBLIQUELY THROUGH THE WIDE CHANNEL INTO A SNUG FIT WITHIN THE SECOND CHANNEL, AFTER WHICH THE EXPOSED PORTION OF THE TUBE CAN BE DRAWN AGAINST A SIDE SURFACE OF THE WIDE CHANNEL TO FORM A FIRST TUBE BEND HAVING AN ANGULARITY CORRESPONDING TO THE ANGULARITY BETWEEN CHANNELS; SAID APPARATUS FURTHER COMPRISING A STRAIGHT SURFACED INSERT STRUCTURE INSERTABLE INTO THE WIDE CHANNEL AFTER THE TUBE HAS BEEN BENT AS AFOREMENTIONED, WHEREBY SAID INSERT STRUCTURE THEN CAUSES THE TUBE TO HAVE A SNUG FIT IN THE SIDE CHANNEL; SAID APPARATUS FURTHER COMPRISING A FORMING MEMBER CARRIED BY SAID BASE STRUCTURE; SAID FORMING MEMBER HAVING A CONVEX CURVILINEAR ANVIL SURFACE LOCATED IN A PLANE ANGLED TO THE PLANE OF THE FIRST AND SECOND CHANNELS; SAID CURVILINEAR SURFACE INCLUDING A SURFACE PORTION ALIGNED WITH THE BOTTOM SURFACE OF THE FIRST CHANNEL, WHEREBY THE TUBE CAN BE BENT AROUND THE CURVILINEAR SURFACE TO EFFECT A SECOND BEND THEREIN. 